US2034357A

US2034357A - Typewriter

Info

Publication number: US2034357A
Application number: US682588A
Authority: US
Inventors: Dwight P Rowland; Conrad C Dahl
Original assignee: Burroughs Adding Machine Co
Current assignee: Unisys Corp
Priority date: 1933-07-28
Filing date: 1933-07-28
Publication date: 1936-03-17
Anticipated expiration: 1953-03-17

Description

March 17, 1936. D. P.'ROWLAND Er AL TYPEWRITER Filed July 28, 1933 4 Sheets-Sheet l INVENTORS 01/44/27 P Paw/am Cnmd QDafi/ ATTQRNEYg 7 March 17, 1936; p ROWLAND ET L 2,034,357

Filed July 28, 1933 4 Sheets-Sheet 4 I NVENTORS Duly/11 P Paw/and Ca/zrad Dal?! 1 ATTOREEYS Patented Mar. 17, 1936 UNITED STATES PATENT OFFICE TYPEWRITER Michigan Application July 28, 1933, Serial No. 682,588

21 Claims.

This invention relates to typewriters, and it has to do-more particularly with margin stop and release mechanism therefor.

The general, object of the invention is to provide an improved typewriter construction.

Another object is to provide an improved margin stop mechanism for limiting the extent of travel of the paper carriage in both directions so that the proper predetermined margin will appear at both the rightand left-hand margins of the paper. a

A further object is to provide an improved margin release mechanism which is operable to disable the margin stop mechanism and permit the paper carriage to be moved beyond both its leftand right-hand marginal limits.

Still another object of the invention is to provide an improved margin control mechanism which is accurately timed with the carriage escapement mechanism to positively position the escapement mechanism to start each successive line of typing at exactly the same left-hand marginal position under all speed and other operation conditions.

Additional objects are toprovide an improved form of margin stop block adapted to be adjustably supported by and at the forward part of the carriage frame; to provide an adjustable stop block support; to provide improved means operable under the control of margin stop mechanism for preventing operation of the type bar operating keys, the space bar, and the universal bar to an escapement operating extent at the end of a line as determined by the margin stop mechanism; to provide an improved single releasable stop means for controlling both the rightand left-hand marginal positions of the paper carriage; to provide means for positively determining the end of movement of the carriage beyond its right-hand marginal position after actuation of the margin release mechanism, which means also serves to actuate means for preventing depressing of the type bar operating keys, the space bar and the universal bar to an escapement operating extent; and to provide structure for carrying out the foregoing objects which is simply and durably constructed, and which is composed of parts which are readily accessible and which may be easily and quickly adjusted and operated.

Other objects and advantages will'become apparent as this description progresses and by referenceto the drawings illustrating one embodiment of the invention wherein:

Figure 1 is a perspective'view illustrating the right-hand marginal stop and release mechanism in normal condition with the typewriter frame, carriage and platen being indicated by dot and dash lines and with the bell ringing means removed;

Fig. 2 is an enlarged, fragmental front elevational view, partially in section, illustrating the right-hand margin block in position preventing further carriagetravel and key depression;

Fig. 3 is a sectional right side elevational view of the structure shown in Fig. 2 and illustrating key locking and universal bar locking means preventing key depression and universal ba'r movement when a margin block is in active stop position;

Fig. 4 is a fragmental perspective view illustrating the margin blocks, their support and the margin stop detent which is associated with both such blocks;

Fig. 5 is a bottom plan view of one of the margin blocks and a portion of its support, certain of the parts being cut away to illustrate the construction more clearly; a

Fig. 6 is a view similar to Fig. 3, except illustrating an active condition of the universal bar lock with the key locking bail in inoperative condition;

Fig. 7 is a fragmentary rear elevational view, partially in section, of the escapement mechanism and illustrating the parts in their respective positions with the escapement mechanism retaining the paper carriage;

Fig. 8 is a view similar to Fig. 7 except illustrating the parts in their respective positions during return movement of the carriage to its left-hand marginal position for the writing of a new line;

Fig. 9 is a view similar to Figs. 7 and 8 illustrating the escapement mechanism parts in an out-of-step condition;

Fig. 10 is "a detail perspective view,'1ooking from the rear, of the means for finally limiting the carriage in its movement to the left as viewed from the front, and

Fig. 11 is a detail section on the line ll-H of Fig. 3.

The typewriter mechanism as a whole includes all those parts requisite in a complete typewriter,

inclusive of a frame I, a traveling paper carriage 2, a case shiftabl platen 3, a type bar mechanism embodying type bars 4, and a key-controlled universal bar 5 which actuates ribbon feed and ribbon vibrator mechanisms. Certain of these mechanisms are not necessaryfor an understanding of this invention, and they have not been illustrated in detail.

Type bar mechanism The type bar mechanism (Figs. 1, 3 and 6) includes a plurality of type bars 4 pivotally supported by a type bar segment 6 for swinging movement toward and from the carriage-supported platen 3. Each type bar is operated by a depressible key lever I connected to the type bar by a crank 8. A key 9 is mounted on the keyboard end of each key lever for depression of the latter.

A frame-carried across shaft l8 supports the cranks 8, and the latter are connected to the respective type bars and key levers by slot-and-pin connections H and I2.

The type bar segment 6 is provided with a plurality of slots, one for each type bar, and each type bar is provided with a cam face l3 which moves in the respective segment slot to actuate the universal bar 5 upon the depression of a key 9.'

Universal bar mechanism The universal bar mechanism is adapted to actuate the carriage escapement mechanism, indicated generally at H (Fig. 1) as well as ribbon feed and ribbon vibrator mechanisms (not shown).

The forward edge of the universal bar 5 (Figs. 3 and 6) is supported by its stud 308 sliding in the segment 5 and this forward edge of the universal bar moves in a curved slot in the rear of the slotted portion of the type bar segment 6 so that its forward edge will be engaged by the cam face I3 of the type bar 4 as the latter is moved toward printing position.

The universal bar 5 is carried by a frame 2| which is supported at its opposite sides for backward and forward movements by a pair of rock arms 22 and 23 (Figs. 1 and 3) carriedby a rock shaft 24 supported bya pair of spaced frame members 25, only one of which is shown in Figs. 3 and 6.

With this arrangement, as the type bar 4 is moved to printing position and its cam face l3 en- I gages the universal bar 5,.the universal bar and its frame 2| are movedrearwardly upon the supporting arms 22 and. 23 and stud 300. During this movement, a lug 25 on the rear part of the universal bar frame 2| engages a part of the escapement mechanism to eifect a carriage escapement action, as will be described more fully hereinafter.

A similar movement of the universal bar is accomplished by a space bar mechanism. More particularly, a space bar 38 (Fig. 1) is supported at the forward part of the machine by a pair of spaced arms 3| fixed to a frame-carried rock shaft 32. This rock shaft supports a rocker arm 33 to which is pivotally connected one end of a lever 34'; the opposite end 35 of which is forked for sliding support by a stud 36 carried by one of the frame members 25. The forked end 31 of lever 34 is extended and provided with a lateral projection 38 which is disposed behind a depending extension 39 on the universal bar supporting arm 22. It will be readily seen that, upon depression of the space bar 30, the lever projection 38 is moved forwardly to engage the arm extension 39 and rock the universal bar supporting arms 22 and 23 and the universal bar 5 rearwardly to effect carriage escapement as in the case of operation of the type bar.v

' Escapement mechanism The escapement mechanism, under the control of the universal bar 5, serves to cause the paper carriage 2 to space toward the left a predetermined distance each time a key 9 or the space bar 38 is depressed and released in order to present a new printing position-on the platen 3 for the next type impression. The paper carriage is adapted to be, urged toward the left by any suitable and well-known spring drum device and, under such urge, the carriage moves to the left a predetermined allotted distance each time the escapement mechanism is actuated.

The escapement mechanism includes an escapement block 48 fixed upon a rock shaft 4| carried by the frame members 25. The escapement block supports an adjustable abutment 42 which is engaged by the universal bar lug 2G in the rearward movement of the universal bar to rock the block 40 in clockwise direction as viewed in Figs. 3 and 6.

The escapement block 40 supports a pair of laterally spaced and diagonally offset escapement paper carriage '2. This rack isconstantly in mesh with a pinion 41 mounted upon a shaft 48 supported at its ends by bearing members 49 and 50 (Fig. 3). The shaft 48, as viewed in Fig. 7, is constantly urged clockwise by the rack 46 and the spring-drum-driven paper carriage 2. A

drum 5| (Fig. '7) is fixed to shaft 48 and in this drum there are mounted a plurality .of pawls 52 which are constantly urged into engagement with the teeth of a ratchet 53 by springs 54.

The ratchet 53 is a fixed part of the escapement wheel which is mounted for free rotation upon the shaft. 48 and which controls the escapement of the carriage. Normally, as viewed in Fig. '7, the drum 5| is urged clockwise by the shaft 48, the pawls 52, at the same time, engaging the'ratchet 53 to urge the latter and the escapement wheel 45 clockwise to engage its tooth 55, for example, with the movable escapement dog 43. The escapement dog 43 is normally urged away from its supporting block 40'by a spring 51; however, in the normal position of the escapement mechanism, as illustrated in Fig. '7, the urge of the carriage is sufficient to move the escapement wheel 45 and the dog 43 to compress the spring 51 so that the dog 43 limits against the escapement block 4|], thereby providing a positive stop for the escapement mechanism and the carriage 2.

Rearwardor clockwise movement of the escapement block 40 shifts the movable dog 43 out of engagement with the escapement wheel tooth 55 and the fixed dog 44 into the path of the tooth 55, thereby permitting the escapement wheel 45 to move clockwise slightly and limit against the fixed dog 44. This action takes place at the end of the down stroke of a key 9 and after the type bar 4 has moved into printing position, and it permits a partial escapement movement of the drum 5| and carriage 2. V

The universal bar 5 is moved forwardly under the urge of a spring'58 (Figs. 3 and 6) acting on the depending extension 39 of arm 22 upon reshaft 4| so that the fixed dog 44 is moved out of engagement with the tooth 55 and the movable dog 43 is moved into the path of the next succeeding tooth 8|. (It will be understood that all ,pf the teeth of the escapement wheel 45 are identical and that they are given different numeral designations herein in order to facilitate description of the escapement action.) mits the escapement wheel 45 to be moved further clockwise under the urge of the carriage 2, and to an extent sufficient'to limit the tooth 6| against the movable dog to complete one full escapement movement. It is to be understood that the dog 43 will rock counterclockwise until limited by the block 40.

This escapement action is repeated upon each depression of a key or the space bar. When the end of a line is reached and thecarriage is returned to its left-hand marginal position, a stop dog 62 prevents movement of the then-floating escapement wheel 45 out of its proper escapement relation. More particularly, return movement of the carriage moves the shaft 48 and drum 5! with its pawls 52 in a counterclockwise direction as viewed from the rear of the machine. During this movement, the parts assume the position illustrated in Fig. 8 wherein the escapement wheel 45 is moved to seat its tooth 63, for example, upon the shoulder 64 of the stop dog 62 and the escapement wheel tooth is slightly released counterclockwise from its normal limiting position shown in Fig. 7, so that the escapement wheel is maintained in a predetermined position against the shoulder 64 by the dog 43 being urged clockwise by the spring 51. When the carriage is fully returned to its right-hand .position, as predetermined by margin stop mechanism, and is then released, the drum 5| and pawls 52 are permitted to rotate slightly clockwise to again engage the proper tooth of ratchet 53 and return the parts to the normal position of Fig. 7 with tooth 55 of the escapement wheel 45 limiting against the movable dog43 which is, in turn, seated against the escapement block 49.

The left-hand margin stop mechanism is so setthat the pawls 52 are rotated a slight distance beyond the particular ratchet teeth 65 to be engaged at the time the margin stop mechanism becomes efiective to stop: the return movement of the carriage. This clearance or lead movement of the pawls 52 may be approximately .025, or less than the pitch of one tooth space on the ratchet 53, for efficient operation of the structure shown. With this arrangement, for any particular left-hand marginal position of the carriage 2, the proper tooth of the escapement wheel 45 will always limit against the escapement dog 43 when the carriage is returned to its lefthand marginal position and each line of typing will always begin at the same marginal position and thereby retain perfect vertical alignment. Further, the escapement pawls 52 will always pick up the proper teeth of ratchet 53 for the foregoing return movement of the escapement mechanism to properly position the paper carriage in its left-hand marginal position. If the foregoing relationship between the parts of the escapement mechanism is changed or interfered with in the operation of the machine, the pawls 52 will not engage and pick up the proper ratchet teeth with the result that the carriage will assume an improper left-hand marginalposition. It will, therefore, be apparent that a definite timed operating relationship exists between the escapement mechanism and the margin stop mechanism.

Margin stop mechanism The margin stop mechanism is provided to ad-' justably limit the travel of the paper carriage in This action perboth directions in order that the proper and desired margin will appear on both the leftand right-hand edges of the paper to be typed upon.

The margin stop mechanism includes rightand left-hand margin blocks 10 and H which are mounted on the forward part of the carriage 2 so as to be readily and quickly accessible for adjustment by the machine operator. These blocks are slidably supported upon the carriage 2 by a rack bar 13.

The margin blocks 10, H are similar in construction, except that they are reversed, and only one of the same will be described in detail. The margin block includes a U-shaped body member 14 which slidably embraces the supporting rack bar 73. A dog 15, which is pivotally mounted at 16 in the open end portion of the block body 14, is provided with 2. depending head portion having a plurality of (preferably, but not necessarily, three) teeth 11 adapted to mesh with the teeth l8 of the rack 13. The dog teeth 17 are constantly urged into mesh with the rack teeth by a leaf spring 19, which has one end thereof secured to the dog 15 at 80 on the side of the dog pivot 16 adjacent the teeth TI. The other and free end of the spring I9 is bowed downwardly so that it projects downwardly across the dog pivot 16 to a point where it is spaced from the U-base of the block body 14 a distance less than the width of rack 13. When the block is mounted upon the rack 13, the spring 19 is, therefore, placed under tension to urge the block dog 15 clockwise about its supporting pivot 16 to yieldably engage its teeth I! with the rack teeth 18.

The dog 15 is provided with a thumb knob 81 and one of the U-arms of the block body is provided with a finger lug 82 located adjacent and substantially parallel to, but slightly spaced from, the thumb knob B I Normally, the block is locked against movement along its supporting rack 18 by the toothed engagement between the dog 75 and rack 13; however, when it is desired to slide or'adjust the block along the supporting rack, the finger members 8|, 82 may be grasped to press the knob 8| against the lug 82 thereby rotating the teeth of the dog 15 away from and out of contact with the supporting rack. With the parts held in this position, the margin block may be moved along the rack to the desired position and the finger hold released at which time the teeth 11 of the dog 15 will again engage the rack to position the block for stopping the carriage.

Each margin block is disposed in horizontal position on the rack bar 13 and the underside of the body thereof is provided with a depending lug 83 which is disposed in the path of a frame-carried stop member 84. When the carriage 2 is moved to the right by the operator, the lug 83 on block H engages the adjacent edge of the stop member 84 and limits further movement of the carriage inthat direction. When the carriage is tabulated or spaced to the left by the depression of keys, or the space bar, or otherwise, the lug 83 of the right-hand marginal block 10 eventually engages the opposite side of the stop member 84 and limits the movement of the carriage in its left-hand travel direction. The foregoing stop means determines both the rightand left-hand marginal positions of the carriage. The marginal position may be readily and quickly varied by changing the position of the margin blocks along the supporting rack 73.

The stop member 85, preferably, forms a part of a lever 85. This lever 85 is provided with an elongated slot 83 intermediate its ends and it is pivotally and reciprocably supported upon a cross frame member 86 by a screw stud 81 which passes through such slot. A coil spring 89 is connected near the end of the stop lever 85 opposite the stop member 84 and also to a fixed stud 89' on the downwardly projecting extension of the cross frame member 86. In this way, the stop member .84 is urged upward into and yieldably held in its normal margin stop position in the path of the stop lugs 83 on the margin blocks I0 and II.

Margin release mechanism The margin release mechanism is provided to enable the operator to disable the margin stop mechanism for movement of the paper carriage beyond either of its predetermined marginal positions. The margin release mechanism is arranged to swing the lever 85 counterclockwise (Fig. 2) to move the stop member 84 downward out of the path of the margin block lugs 83 so that the carriage may be moved in either direction beyond the position normally determined by the margin blocks. This action is accomplished by the actuation of a margin release key 90.

The margin release key 90 (Figs. 3 and 6) is supported and guided for vertical reciprocatory 98 upon which the underside of the right-hand end 99 of the stop lever 85 seats to normally hold that end of the stop lever in a predetermined position locating the stop member 84 in the path of the margin block lugs 83.

' The stop member 84 may be released or disabled by depressing the release key 90, thereby swinging the lever 92 to elevate the lever 95 and,

in turn, elevate the abutment or right-hand end of thestop lever 85 to lower its other end and the stop member84 out of the path of the margin block abutments 83.

It will be seen from the foregoing that a single frame-carried stop member serves to position the carriage in both its right-hand and lefthand marginal positions; and that a single release key is operable to disable this stop device to permit movement of the carriage to the full limit of its travel in both directions. That is to say, to move the carriage 2 either to the right or left after the respective margin block engages the stop member 84, it 'is only necessary to depress the margin release key 90 to lower the stop member 84 and then move the carriage manually in the desired direction.

As the carriage moves beyond the stop member 84 in either direction, the spring 89 returns the stop lever and its stop 84 to their normal positions of Fig. 1 and it also acts through lever 85 to restore the release key 90 and its connections to their normal positions. Although, at this time, the stop member 84 is again disposed in the path of the respective margin block, it is disabled by the respective margin block in the return movement of the carriage to within its normal margin limits as follows:

The stop ugs 83 on both margin blocks are rigidly brac d upon the margin ,block body 14 by web portions constituting cam members I00.

These cam members are aligned with the stop member 84 and they taper gradually upward from the lower edge of the margin block lugs 83 to the margin block body 14 so that they readily engage and depress the stop member 84 as they pass thereover on the return. That is to say, for example, in movement of the carriage to the left from a right-hand position where in its margin block II is disposed to the right of the stop member 84, he cam surface I00 of the margin block II engages the top of the stop member 84 and depresses it out of the path of the block stop 83 until the margin block moves therebeyond. This same camming action takes place with respect to the margin block 10 in movement of the carriage from a left-hand position wherein its margin block I0 is disposed to the left of the stop member 84. In other words, the margin release key 90 must be manually depressed to permit the carriage to move to the right or left beyond its J normal marginal positions, but the cam members I00 on the margin blocks I0, II disable the stop member 84 when the carriage is returned in either direction to within its normal marginal limits.

The right-hand margin block I0 also actuates a signal which warns the operator that the righthand marginal limit is being closely approached. In the tabulation or spacing of the carriage to the left, the lug 83 on the margin block 10 engages the cam face IOI of a pass-by pawl I02 a few spaces in advance of its point of engagement with the stop member 84. Pass-by pawl |02-is pivotally supported upon one end of a bell-hammer lever I03 which is, in turn, pivotally supported at I04 by the frame cross piece 86. The pawl end of lever I 03 is provided with a lateral lug I05 disposed behind the pawl I02 to prevent counterclockwise rotation of the pawl I02 when it is engaged by the margin block lug 83; wherefore, as

the margin block lug 83 moves over the cam sursupports a bell-hammer I06.

Movement of the margin block I0 beyond the pawl I02 releases the lever I03 and permits its hammer I 08 to fall and strike a bell I01. The bell lever I03 is held normally with its hammer end downward adjacent the bell I01 by a spring I08 connected thereto adjacent the hammer and to a fixed frame-carried member (not shown). It will, therefore, be seen that the lever I03 is rotated counterclockwise by the margin block against the urge of spring I08 so that as the margin block moves beyond the cam surface of the pawl I02 the spring will return the lever I03 and hammer I03 in clockwise direction to their normal positions (Fig. 2) with sufiicient force to cause the hammer I06 to strike thebell I0! and give the desired warning. This warning signal is given a sufficient time ahead of engagement of the margin block I0 with the margin stop 34 to permit the operatorto gauge the number of letter spaces available in that particular line before the carriage is finally stopped by the margin stop mechanism.

7 The bell lever or pass-by pawl I02 is mounted to partially rotate in a clockwise direction so that,

as' the carriage is returned to its normal righthand position, the stop member 83 of margin block 10 strikes and moves the pawl I02 clock- J wise out of the path of the margin block without interfering with the position of the bell hammer lever I03. The underside of the pawl I02 is slightly enlarged to provide sufficient weight thereat to insure that the pawl will swing back to its normal upright position of Fig. 2 after the margin block has passed thereover as just stated.

When the margin block 10 engages the stop member 84, further full depression of the keys 9 is prevented. Otherwise, depression of the keys with the carriage incapable of further movement would result in several letters being printed one on top of the other.

To positively insure against key depression at the end of a line under all conditions of operation, including high speed operation or otherwise, this invention contemplates the provision of dual locking means for both the keys 9 and the universal bar 5. This means is controlled by margin stop mechanism when the end of a line, as determined by a margin stop, is reached.

Key lock The key lock includes a bail H disposed crosswise of the machine beneath the type bar and space bar levers I and 3|, respectively. This bar is provided with a longitudinal rib adapted to give strength thereto and it is also provided at its opposite ends with laterally turned ears H2 which are pivotally connected to the opposite sides H4 of the machine frame by pins H3 (Figs. 1 and 3). The upper edge of this bar is turned over to provide a fiat surface adapted to be engaged under certain conditions by the depending arms H5 and H6 on the key and space bar levers I and 3|, respectively, when the keys 9 and space bar 30 are depressed.

The key lock bail H0 is' normally held in position out of the path of the key lever and space bar arms H5, I I8; however, upon engagement of the margin block 10 with the stop member 84, this bail H0 is rotated clockwise to position its upper edge beneath the key lever and space bar arms to prevent depression of the key and space'bar levers 1, 3I to an extent suflicient to move the type bars 4 to printing position by the key levers I, or to cause a mis-operation of the escapement by depression of the space bar 30. Blocking a depression of the key lever I and space bar arms 3| prevents actuation of the universal bar and the consequent escapement movement of the paper carriage.

Specifically, as shown in the drawings, the

right-hand end of the stoplever 85 (Fig. 2) is provided with a lateral pin H! which is received within-the forked end H8 of a crank H9. Crank H8 is pivotally supported by the stud 91 that is received in the slot 95 of the upright release lever 95. A downwardly extending lever I20 has its upper end pivotally connected to the crank H9. and the lower'end of this lever i connected to the right-hand lateral ear H2 of t e'key lock bail H0 by a stud and slot connection I2I, I22. The stud I2I is constantly urged into and yieldingly held in the lower end of the slot I22 by a spring I23 so that the key lock bail H0 is held in its released normal position of Fig. 1 and it will be moved immediately to a key locking position in response to downward movement of the vertical lever I20.

Engagement of the right-hand margin stop 10 with thestop member 84 moves the stop lever 85 to the left, this being permitted-by the stud and

slot support

81, 88 of this lever. As the stop lever is thus moved, the crank H9 is moved counterclockwise to shift the lever I20 downwardly and. in turn, rock the key looking bail.

II 0 clockwise to the position of Fig. 3 wherein its upper edge is disposed directly beneath the frame.

arms H5, H6 on the key levers 1 and space bar levers 3|, respectively. Depression of the key or space bar levers to an escapement or printing extent is thus prevented.

The stop member 84 and the margin block 10 are preferably, so relatively positioned that only a single escapement action of the escapement mechanism isnecessary to move the key locking bail I I0 into position to block full depression of the keys and space bar. That particular escapement movement just previous to engagement of the margin block with the stop 84 positions the margin block 10 at such a point that there is but a very slight clearance between it and thestop 84. In other words, these parts should be so related that when the carriage and its block 10 move during the next succeeding escapement operation, the block 10 shifts the stop lever 85 to the left substantially a full escapement movement. For the purpose of this description, it may be assumed that the length of each escapement movement is .100"; but it is to be understood that the length of this movement may be varied according to the size, character, etc. of the type employed and other conditions of use.

When using an escapement movement of .100",

the slot 88 in the stop lever 85 is of approximately .125" in length so that there is approximately .025" slot clearance after the movement of the stop lever 85, and this insures that this movement? the open ends of similarly-constructed U-shaped brackets I30, the closed ends of which support adjustment screws I3I. The opposite ends of the rack I3 are provided with elongated slots I32, and screw bolts I33 pass through the carriage frame member I34, the U-shaped supports I30 and the slotted rack openings I32 to receive a nut I35 for securely mounting the rack and its supports upon the forward part of the carriage The rack 13 may be adjusted relative to the stop member 84 by loosening one of the screws I3I and tightening the other to shift the rack longitudinally to the desired extent. Lock nuts I36 are mounted upon the projecting portions of the screws I3I to maintain the predetermined adjustment of the rack as well as'to shield the screws I3I against accidental movement. By thus adjusting the rack I3, the margin I sary for positioning thecarriage in its proper left-hand marginal position as hereinabove more particularly set forth.

Universal bar lock The universal bar lock prevents movement of the universal bar 5 to effect an escapement action after engagement of the margin block I0 with the margin stop 84 should the key locking bail IIO fail to prevent a subsequent key depression.

,Although the key locking bail I I0 normally prevents key depression and escapement action after the right-hand margin block I0 engages the margin stop and moves a full escapement distance, an extremely rapid operator may be able to depress a second key after a first key has been depressed to actuate the margin stop and before the key locking bail IIO has been moved into its key-blocking position. Depression of the first key results in a full carriage escapement movement in the manner already explained, and the depression of a second key under the above conditions causes the proper type bar to be moved to printing position so that a print by the second key depression is made on the paper but not necessarily in the proper position. Its position may vary up to .025" out of the proper place due to the extra .025" movement of the stop lever 85. This condition, however, causes an incomplete escapement so that when the carriage is returned to its left-hand marginal position the next printed line will start one space out of its proper marginal position, namely, one space to the right of its left-hand marginal position.

More particularly, the full escapement action under the control of the first key which actuated the margin stop mechanism will shift the paper carriage 2 and the stop lever 85 one full space to the left. Since the slot 88 in the stop lever 85 is long enough 'to accommodate only one fullescapement movement plus .025", the carriage 2 can travel only .025", or an incomplete escapement distance, upon actuation of a key following the operation of the margin stop mechanism.

Therefore, when a second key is depressed before the first key (the one which operates the margin stop mechanism) is restored and before a sufficient escapement movement of the carriage 2 takes place to set the key locking bail III] to prevent further key depression, the universal bar 5 is again actuated by the second key to effect an escapement action. However, since the carriage 2 can move only .025" to the left, the escapement mechanism assumes only a partial escapement position 'such, for example, as that illustrated in'the "out-of-step condition of Fig. 9.

In this partial escapement position of the carriage and escapement mechanism, the carriage improperly limits against the margin stop 84 rather than against the escapement dog 43. That is to say, in this partial escapement action, the escapement wheel tooth 55, for example, which should be engaged with and seated upon the dog 43, as shown in Fig. '7, is moved clockwise past the dog 43, thereby positioning the ratchet 53 so that the drum-carried pawls 52 will pick up, for example, the ratchet tooth 66 instead of the proper ratchet tooth 65 when the carriage is returned to the left and released. At this time, since the escapement wheel tooth 55 has moved clockwise beyond the dog 43, the drum 5| under the urge of the carriage 2 will be rotated clockwise to engage the similar and next succeeding escapement wheel tooth 6| instead of the proper tooth 55 with the dog 43. Th\- carriage will thereby be returned to aposition wherein the next printed intended left-hand mar inal position.

The universal bar lock (Figs. 3 and 6) prevents any escapement action after the margin stop is engaged so that the escapement mechanism, when an end of a line is reached, always assumes the proper in-step condition illustrated in Fig. 7.

The universal bar lock is controlled by the margin stop mechanism and is inter-connected with the control parts of the key locking bail H0 in such a way that it is actuated slightly in advance of the keylocking bail. The universal bar lock is so timed that it, preferably, assumes an operable locking condition almost immediately after engagement of the margin block I0 with the stop 84 and prior to the completion of the margin block movement or movement of the key locking bail IIO to its operative key stop position of Fig. 3.

' The universal bar lock includes a crank I40 pivotally supported by a frame-carried stud I4I. One arm of this crank is pivotally connected to. the adjacent vertical lever I20 which is also connected to and operates the key locking bail IIO as already described. The other arm of crank I40 is pivotally connected to one end of a rearwardly and horizontally extending lever I42 which has its other end pivotally connected to a rock arm I43 secured to a right-angularly disposed and frame-carried rock shaft I44.

. The rock shaft I44 adjacent its end opposite the arm I 43, supports a rearwardly extending hook arm I45. The hook end I4'I of this arm I45 is adapted to extend over and rearwardly behind a lateral pin I46 carried by one of the rock arms 23 which support the rear portion of the universal bar frame 2I.

When the parts are in their normal positions of Rig. 1, the vertical lever I20 is held raised by the spring 89 thereby holding the universal bar lock hook I41 raised out of the path of the universal bar lock pin I45. As the margin block I0 engages the margin stop 84 and shifts the stop lever 85 to the left, the lever I20 is shifted downwardly by the counterclockwise movement of the crank II9 to, in turn, rock the universal bar lock crank I40 in counterclockwise direction, as viewed in Figs. 3 and 6. This rocking movement of the crank I40 shifts the lever I42 forwardly and moves the hook arm l45 downwardly with its hook end I41 behind and in the path of the universal bar locking pin I46. The downward movement of the vertical lever I20 is permitted, even though an arm I I6 of a key may be in position'to prevent movement of the key locking bail IIO clockwise to its key stop position (Figs. 3 and 11) by the yieldable slot and pinconnection I 2|, I22 between the key locking bail ear I I2 and the lever I20. That is to say, while the spring I23 normally holds the pin I2I of this connection in the lower part of the slot for operation of both the locking bail H0 and lock arm I45, this spring will yield and permit depression of the lever I20 to actuate the lock arm I45 whilethe lock bail I I0 remains stationary, as illustrated in Fig. 6.

The lock arm I45 is so positioned upon its shaft I44 that, upon a very slight downward movement of the lever I20, it .assumes a position preventing rearward movement of the universal bar to an escapement extent. This lock becomes eifective slightly in advance of movement of the key locking bail IIO to its full key stop position.

Movement of arm I45 is so timed that, even though a key 9 may be depressedafter the margin stop is engaged, the universal bar 5 cannot be actuated to effect an escapementaction. Also, the type bars 4 cannot be movedinto printing universal bar blocks such movement.

Final carriage stop Following engagement of the margin block 10 with margin stop 84 and depression of the margin release key 90, the carriage may be moved to the left a limited number of letter space movements. This movement is positively stopped by a final stop mechanism which is engaged and actuated by the carriage. This final stop mechanism not only nonreleasably and positively regulates the end of a line of movement of the carriage 2 to the left after releasing the right-hand margin stop, but it also actuates the key lock and universal bar lock mechanisms hereinbefore described, positively preventing actuation of keys 9, and space bar 3|, at the extreme end-of the movement of the carriage to the left.

The final carriage stop mechanism (Figs. 2, 3 and 10) includes a slotted side plate 200 supported on the underside of the front carriage rail 26! by shouldered screws 202. The slide plate 200 normally floats on the carriage rail .and it is provided at its right hand end, as viewed from the front of the machine, with a downwardly projecting ear 203'adapted for engagement with a horizontal and rearwardly projecting stud 204 carried by the stop lever 85. The left end of t e slide plate 206 is turned horizontally rearward and then upward to provide an upstanding arm 205 which is disposed in the path of the right side carriage end frame member 206.

As the carriage reaches its left-hand movement limit beyond the margin block 10, the carriage frame member 206 engages the slide plate arm 205 and shifts the slide plate 200 to the left, as viewed in Fig. 2, the extent of movement of such plate being limited by the ends of the slide plate slots 201 engaging the screws 202. The slide plate ear 203 is normally located closely adjacent the stop lever stud 204, and, as the carriage engages and moves the slide plate 200, to the left, the slide plate 200 picks up and shifts the stop lever 85 to the left. These parts are so related that, in the foregoing operation, the stop lever 85 is shifted, preferably, one full escapement step to the left.

This shift movement of the stop lever 85 rocks the bell crank H9 counterclockwise to depress the vertical lever I20 and rock the key locking bail H0 to its Fig. 3 position wherein depression of the keys 9 and space bar 3| is prevented. This downward movement of the lever l20 also serves to rock the hook arm I45 of the universal bar lock thereby blocking rearward movement of the universal bar 2| and, in turn, depression of the keys 9 and space bar 3| as hereinbefore more fully described.

The number ,of letter spaces or escapement "movements permissible after the margin block 10 engages the margin stop 84 and upon actuation of the release key 90 is determined by the position of the margin block 10 on the rock bar 13.

Operation Theleft-hand marginal position of the carriage may be located by adjusting the margin block H to the desired position upon its rack 13. This position may be determined by a scale (not shown) associated with the carriage frame above the rack 13 where it will be constantly within the vision of the operator. To facilitate setting of the margin block H to a predetermined marginal position indicated upon the platen-carried paper, scale means (not shown) corresponding to the margin block scale means may be associated with auxiliary pressure roll structure 2! (Figs. 3 and 6) so that this margin block may be set along its scale to agree with a position on the paper as indicated by the scale immediately adjacent the paper. Both of these scale means may be so located as to be constantly within the vision of the operator at all times.

' The right-hand marginal position of the car,- riage is likewise determined by similarly adjusting the margin block 10. v

Further operation of the structure shown will be readily understood from the foregoing description.

It is to be understood that the structure shown is for purposes of illustration only and that varia-' tions may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. In a typewriter, amovable platen carriage, depressible key levers for operating type bars, a universal bar actuated by the type bars, means for normally limiting movement of said carriage to the left and to the right to predetermine rightand left-hand marginal positions of said carriage, means for locking said key levers against depression, separate means for locking said universal bar against movement, and means including a single train of connections for actuating both said locking means by said carriage movement limiting means assaid carriage moves to its right-hand marginal position.

2. In a typewriter having a frame, a carriage, type bars, depressible keys for moving said type bars to printing position, a universal bar actuated by said type bars, and escapement mechanism actuated by said universal bar, the combination of margin stop means carried by said carriage, a margin stop member carried bysaid frame and adapted to be engaged by said carriage-carried stop means, and separately operable locking means actuated by said stop member through a single-train of connections as it is engaged by said carriage-carried stop means for separately preventing depression of said keys to an extent sufficient to move said type bars to printing position and preventing movement of said universal bar to an extent sufficient to actuate said escapement mechanism. r

3. In a typewriter having a frame, a carriage, type bars, depressible keys for moving said type bars to printing position, a universal bar actuated by said type bars, and escapement mechanism actuated by said universal bar, the combination of margin stop means carried by said carriage, a margin stop member carried by said frame and adapted to be engaged by said carriage-carried stop means, key locking means for preventing depression of said keys to an extent sufficient to move said type bars to printing position, universal bar locking means for preventing movement of said universal bar to an extent suflicient to actuate said escapement mechanism, and connections between (said frame-carried stop member and both said key locking, and universal bar locking means for actuating the latter as saidframe carried stop member is engaged by said carriage-carried stop means. Y

4. In a typewriter having a frame, a carriage mounted for movement on said frame, type bars, 1

keys for moving said type bars, a universal -bar actuated by said type bars, and escapement mechanism actuated by said universal bar, the combination of a margin block adjustably mounted on said carriage, a stop lever slidably mounted on said frame and having a stop member thereon adapted to be engaged by said margin block at the end of a typed line to shift said stop lever in the direction of movement of said carriage, a

member swingably mounted beneath said keys and adapted in one position thereof to be engaged by said keys to block operative depression of the latter, connections between said stop lever and'said key blocking member, another member swingably mounted adjacent said universal bar and adapted in one position to engage the latter and block movement thereof, and means connecting said universal bar blocking member to first-named connections for actuation of both said blocking members to their blocking position as said margin block engages said stop member and shifts said stop lever.

5. In a typewriter having a frame, a carriage mounted for movement on said frame, type bars, keys for moving said type bars, a universal bar actuated by said type bars, and escapement mechanism actuated by said universal bar, the combination of a margin block mounted on said carriage, a stop lever mounted on said frame for longitudinal shift movement equal-at least to the length of one complete escapement movement of said carriage, a stop element on said stop lever disposed normally in the path of said margin block and adapted to be engaged by said margin block to shift said stop lever approximately one full escapement distance, key locking means disposed normally in an inactive position, universal bar locking means disposed normally in an im active position, and means interconnecting said two locking means and said stop lever with each other and arranged to move said two locking means to active key and universal bar locking psition at least by the time said lever has completed its said complete escapement distance movement.

6. In a typewriter, the combination of a carriage, type bars, keys for operating said type bars, a universal bar actuated by said type bars, escapement mechanism operated by said universal bar, a margin block on said carriage, a slidably mounted stop member adapted to be engaged by said margin block at the end of a typed line, a normally inactive key lock, anormally inactive universal bar lock, connections between said stop member and said key lock including a lever for moving said key lock to a position to block depression of said keys upon slide movement of said stop member as it is engaged by said margin block, and connections between said lever and said universal bar lock for also moving the I latter to a position wherein it blocks movement line, a normally inactive key look, a normally inactive universal bar lock, connections between said .stop member and said key lock including-a lever for. moving said key lock to a position to block depression of said keys upon slide movement'of said stop member as it is engaged by said margin block,and connections between said lever and said universal "bar lock for also moving the latter to a position wherein 11 blocks movement of said universal bar, saidlever having a yieldable connection with said key lock permitting movement of said lever to actuate said universal bar lock should movement of said key lock be blocked.

8. In a typewriter having a frame, a platen carriage movably supported thereby, type bars operated by key levers, a universal bar actuated by said type bars, and escapement mechanism operated by said universal bar, the combination of a stop abutment on said carriage, a stop lever shiftable to a limited extent on said frame and having a stop element on one end disposed in the path of said stop abutment, a member movable to a position to block depression of said key levers, another member movable to a position to block movement of said universal bar to an extent suflicient to actuate said escapement mech-.- anisrn, a bell crank connected to said stop lever opposite said stop element, a connection between said bell crank and said key lever blocking member, another bell crank connected to said connection, and a connectionbetween said second bell crank and said universal bar blocking member, whereby both said, blocking members are moved to their blocking positions as said stop leveris shifted b engagement of said stop abutment with said member. a

9. In a typewriter having a frame, a carriage, type'bars, depressible key levers for operating said type bars, and aluniversal bar operated by said type bars, thei ombination of a margin block mounted on said carriage and having a stop element thereon, a stop lever mounted on said frame for longitudinalshift movement and having a stop member thereon adapted to be engaged by said stop element,"a locking bail swingably mounted beneath said key levers for movement from a normally inactive to an active position preventingoperative depression of said key levers, a separate locking device associated with said universal bar to prevent movement of the latter, and means connecting said locking bail and locking device with said stop member lever including a bell crank connected to said lever, a reciprocable lever connected to said bell crank, a link element between said reciprocable lever and said lock device and a slotwand-pin connection between said reciprocable lever and said locking bail permitting movement of said reciprocable lever to actuate said lock'device independently of said locking frame for rotary swing and longitudinal shift movements and having a stop member thereon adapted to be engaged by said stop element, a locking bail swingably mounted beneath said key levers for movement froma normally inactive to an active position preventing operative depression I of said key levers, a lock device associated with said universal bar and adapted to prevent movement of the latter, and means connecting said locking bail and lock device and said stop member lever including a bell crank connected to said lever, a reciprocable lever connected to said bell crank, and a'yieldable connection between said reciprocable lever and said locking bail permitting actuation of said lock device by said stop member throughsaid connecting means indeplaten-supporting carriage movably mounted thereon, margin stop means which includes a pair of margin blocks mounted on said carriage for adjustment longitudinally thereof and each having a stop member thereon, a single reciprocable stop element mounted on said frame, means for yieldably urging said reciprocable stop element into a raised. position to be engaged by both said margin block stop members to limit movement of said carriage in one direction and determine one marginal position thereof, manual means for lowering said reciprocable stop element out of the path of said margin block stop members to permit movement of said carriage beyond either of its predetermined marginal limits, and cam means on both said margin blocks for bracing said stop members and for'engaging and depressing said stop element out of the path of said margin blocks without disturbing said manual means during movement of the carriage and margin blocks from positions beyond the marginal limit normally predetermined by said margin blocks to a position normally within said marginal limits.

12. In a typewriter having a platen carriage, type bars, depressible keys for operating said type bars, a universal bar actuated by said type bars and escapement mechanism actuated through the operation of said universal bar, the combination of means for positively stopping said carriage in a selected right hand marginal position, means for releasing said stop means to permit movement of said carriage beyond said selected marginal position, means beyond said stop means for stopping said carriage in a final stop position beyond said selected marginal position, and means actuated by both said stop means for preventing depression movement of said keys and independently preventing escapement-operationmovement of said universal bar. I

13. In a typewriter having a frame, a platen carriage thereon, and escapement mechanism, means for preventing actuation of the escapement mechanism when the carriage reaches the end of its movement in one direction, said means including a plate mounted on the frame for limited longitudinal shift movement and adapted to be engaged by the carriage when the latter reaches the end of its movement, a lever mounted on the frame for limited longitudinal shift movement and adapted to be engaged by said plate in the shift movement of the latter by the carriage, locking means movable to a position to block actuation of the escapemht mechanism, and connections between said locking means and said lever whereby said locking means is moved to its blocking position upon shift movement of said plate by the carriage.

14. In a typewriter having a frame, a platen carriage thereon, a universal bar and escapement mechanism operated thereby, means for locking the universal bar against movement when the limit of movement of the carriage in one direction is reached, said means including a plate mounted on the frame for shift movement and adapted to be engaged and shifted by the carriage as it moves to its movement limit, a lever mounted on the frame for shift movement and adapted to be engaged and shifted by said plate, normally inactive means for locking the universal bar against movement, and means connecting said lever and locking means for movement of the latter to locking position upon shift movement of said plate by the carriage. I

15. In a typewriter having a frame, a platen carriage thereon, depressible type bar operating keys, a universal bar operated by depression of the keys and escapement mechanism operated by the universal bar, means for locking the keys against operative depression movement when the limit of movement of the carriage in one direction is reached, said means including a plate mounted on the frame for shift movement adapted to be engaged and shifted by the carriage as it moves to its movement limit, a lever mounted on the frame for shift movement and adapted to be engaged and shifted by said plate, a normally inactive device for blocking movement of the keys, and means connecting said lever and device for movement of the latter to key blocking position upon shift movement of said plate by the carriage.

16. In a typewriter having a frame, a platen carriage thereon, depressible type bar operating keys, a universal bar operable by depression of the keys, and escapement mechanism operated by the universal bar, means for preventing escapement movement of the carriage when the limit of its movement in one direction is reached,

said means including a plate member mounted on the frame for limited shift movement and adapted to be engaged and shifted by the car= riage as it moves to its movement limit position, a lever mounted on the frame for limited shift movement and adapted to be engaged and shifted by said plate, normally inactive means for blocking movement of the universal bar, normally inactive means for blocking depression of the keys, and means interconnecting both said locking means and said lever for movement of said locking means to operative locking position upon shift movement of said plate by the carriage.

17. In a typewriter having a frame, a platen carriage thereon, depressible type bar operating keys, 2, universal bar operated by the keys, and escapement mechanism operated by the universal bar, a margin stop mechanism including a stop member on the carriage adjustable for limiting movement of the carriage in one direction to a selected marginal position, a stop member on the frame having limited shift movement and adapted to be engaged by the carriage stop member for limiting the carriage to said selected marginal position, locking means associated with the keys and universal bar and normally inactive, connections between said locking means and said frame stop member for moving said locking means to-locking position upon engagement of said stop members, means for releasing said frame stop member to permit movement of the carriage beyond the selected marginal position determined thereby, a shiftable member on the frame adapted to be engaged by the can'iage in a final stop position of the carriage beyond its said selected marginal position, and a connection between said shiftable member and said shiftable stop member for actuation of ,the latter to move said locking means to locking position as the carriage reaches its said final stop position.

l8. Margin stop mechanism for a typewriter having a frame and a platen carriage thereon,

movement equal at least to one complete escapement movement of said carriage, said stop lever having a stop element on one end thereof adapted to be engaged by said stop abutment in one marginal position of said carriage, escapementmovement-prevention means connected to the other end of said stop lever and actuated thereby, and means for adjusting said bar member longitudinally of said carriage to position 'said stop abutment to permit at least one complete escapement movement of said carriage after said stop abutment engages said stop element.

19. Margin stop mechanism for a typewriter having a frame and a platen carriage-thereon, which includes a rack bar mounted on said carriage longitudinally thereof, a *margin block mounted on said bar-and having means adjustable to engage the teeth of said bar in different positions of said block thereon, a stop lever mounted on said frame for longitudinal shift movement somewhat greater than one complete escapement movementlof said carriage, a stop element on one end of said stop lever adapted to be engaged by-said margin block when a marginal position of said carriage is reached, locking means preventing escapement movement of said carriage connected to and actuated by the other end of said stop lever, and means for adjusting said rack bar longitudinally of said carriage to so position said margin block relative to said stop element as to cause the former toflengage the latter at such a time that the carriage can move substantially one complete escapement movement after engagement of said margin block with riage, a margin block mounted on said rack bar ,and having means selectively engageable with the teeth of -said bar for holding said block in different positionsalong said bar, a stop abut ment on said block, a stop member on said frame adapted to be engaged by said stop abutment in a marginal position of said carriage, and means for mounting said bar on said carriage including U-shaped supports receiving the opposite ends of said bar, said bar having slots in its opposite ends, members securing said U-shaped supports to said carriage and passing through said bar slots to prevent lateral displacement thereof, and adjustable members carriage by said U-shaped supports and engaging the opposite ends of said bar for shifting the latter longitudinally relative to said U-shaped supports. 1

21. In margin stop mechanism for typewriters, a margin block and means for supporting said margin block which includes a rack bar upon which said margin block is slidably supported, said margin block having. means engaging the teeth of said rack bar to'hold it in adjustedposition on said rack bar, U-shaped supports receiving the opposite ends-of said rack bar, said rack bar having elongated slots in its opposite end portions, means adapted for securing said supports to a platen carriage and extending freely through said bar slots, adjusting screws carried by said supports and engaging the opposite end edges of said bar.

- DWIGHT P. ROWLAND.

CONRAD C. DAHL.